The present invention relates to a semiconductor apparatus, an oscillation circuit, and a signal processing system.
There are various kinds of crystal resonators with different oscillation frequencies and load capacitance values. In an oscillation circuit composed of a crystal resonator and a semiconductor chip, the semiconductor chip has heretofore been peculiarly designed according to an oscillation frequency and a load capacitance value of the crystal resonator. Therefore, the semiconductor chip in the oscillation circuit could not generate an oscillation signal using a crystal resonator different from the originally provided one.
A related technique is disclosed in Japanese Unexamined Patent Application Publication No. H01-317004 and Japanese Unexamined Patent Application Publication No. 2006-287765.
Japanese Unexamined Patent Application Publication No. H01-317004 discloses the oscillation circuit including the switched capacitor circuit that is configured to include a plurality of series circuits that are composed of capacitances and switches and at least one of series circuits that are composed of capacitances, resistances, and switches, in which the plurality of series circuits that are composed of capacitances and switches and at least one of the switches that are composed of capacitances, resistances, and switches are connected in parallel with each other. With such a configuration, the oscillation circuit can compensate temperatures with high accuracy.
Japanese Unexamined Patent Application Publication No. 2006-287765 discloses the crystal resonator including the inverter that is capable of changing the size of the inverter.